One of the things I noticed is that while I write and give talks lot about the philosophy of science, I get most pushback when I criticize Popper’s falsifiability idea (such as in my Scientific American article The Idea that a Scientific Theory can be ‘Falsified’ Is a Myth: It’s time we abandoned it) than any other thing I say. What is interesting is that I get challenged by both scientists and intelligent design creationists, who are usually on opposite sides of discussions about the nature of science. For example, at Why Evolution Is True, evolutionary biologist Jerry Coyne (and his commenters) disagreed with my article. And over at Evolution News intelligent design creationist David Klinghoffer also disagreed with me.
Both seem to want to preserve strong versions of falsifiability but for different reasons. Scientists like it because it has long been a part of scientific folklore that they pick up along with their scientific education, that falsification is how science progresses and is the mechanism by which old theories get overthrown to be replaced by newer and better ones, thus implying that science is relentlessly progressing, getting better and better. Falsification is also used as a rule to keep out of science ideas like intelligent design creationism, whose proponents seek to bestow upon their theory the prestige of being labeled a science. Intelligent design is said to be not falsifiable and is thus not science.
Opponents of the scientific consensus in specific areas such as climate change, vaccines, and evolution, like falsification because they think it provides them with a means to undermine the scientific consensus that they dislike in any field. It allows them to find (or manufacture) this or that result that disagrees with the predictions of the theory and triumphantly claim that the scientific consensus has been falsified and should be rejected in favor of their own pet theory.
But as I show in my book The Great Paradox of Science, the naive version of Popper’s falsification was quickly shown by other philosophers of science to be untenable and the reasons why the scientific consensus is so reliable and should be trusted can be found elsewhere in scientific practice. But that more sophisticated view has not percolated to the general public who hold on to Popper’s original formulation and defend it vigorously.
This reminded me of how, in socialist political circles, some people are derisively described as being ‘more Marxist that Marx’, by which it is meant that they are often more extreme and rigidly doctrinaire about what views Marx held than Marx was himself. I think that it is similar with Popper. People are so enamored with his naive falsifiability idea (it has an appealing simplicity that makes it easy to understand) that they have embraced a version of it that is stronger than what Popper himself held, especially later in his life. He backed away from the naive formulations as he conceded that there was no such thing as pure sense-data, observations that were uncontaminated by theory, and this undermined the naive view.
Given that part of Popper’s motivation for formulating falsification was because of his antipathy to Marxism and his desire to find a definition of science that would exclude it from being considered scientific, it is ironic that he finds himself in the company of Marx in having their respective supporters taking their ideas further and applying them more rigidly than they themselves would or did.